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<DIV><FONT face=Arial size=2>Use tapered wire.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=halken@comcast.net href="mailto:halken@comcast.net">Hal Kennedy</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=secc@contesting.com
href="mailto:secc@contesting.com">secc@contesting.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, August 24, 2007 3:48
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> **Possible_Spam** [SECC]
Reference for radial discussion</DIV>
<DIV><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">The concentric radial approach I
mentioned I thought was discussed within the 564 page book: Radio Antenna
Engineering, by LaPorte. This is a classic and good addition to anyone’s
antenna library – particularly considering the price – free.</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Go to <A
href="http://www.lulu.com">www.lulu.com</A> and type “Antenna
Engineering” into the search box. It’s the first book returned in the
search. You can download all 33Meg for free.</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Meanwhile, I can’t find the
particular radial approach I was thinking of in the book, although many
different radial schemes are discussed.</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Concentric
system:</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">The problem with radials that
simple radiate out from a central point is that they do not cover each square
meter of ground equally well. They are spaced far apart at the ends and
tightly bunched at the center. To get a “really good” radial system it
is sometimes recommended that 120 radials be used or the ends be no more than
0.02 wavelength apart – broadcasters frequently use 120. For the first
few feet from the tower its nothing but solid copper and most of this is
wasted. The alternative is as follows:</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Suppose you want a 64 radial
system of 100 foot radials. Place a concentric circular loop wire 33
feet out from the center and another 66 feet out from the tower. Connect
16 radials from the center to the fist ring wire, 32 radial wires from the
first ring wire to the second, and 64 wires outward from the outer ring wire
to 100 feet. In all cases the wires should be equally spaced around in
azimuth angle. This system will use around 55% as much copper as 64 full
sized radials (I forget the exact ratio) and yield the same performance.
Soldering all the wires to the ring loops however, is a lot of extra
work. If its going to be in or on the ground for a long time then
regular solder should not be used either – it should be silver
solder.</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">73</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Hal</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">N4GG</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">
</SPAN></FONT></P></DIV>
<P>
<HR>
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